In U.S. Pat. No. 3,899,218 of Gary D. Blomstrom et al, which patent is owned by the assignee hereof, an improved track roller frame construction is disclosed for use with a track-type vehicle. The track assembly includes an idler supported for rotation on a pivot pin and for axial rocking movement by a pair of pin-supporting carriages disposed on either side of the idler. The carriages are individually pivotally connected to the track roller frame and each includes a rearwardly inclined arm connected to a yoke assembly by a pivot pin. The yoke assembly, in turn, is pivotally secured to a transverse pin carried by a connecting rod resiliently axially loaded by a recoil mechanism.